1. Field of the Invention
The field of art to which this invention pertains may be generally located in the class of devices relating to work forming processes. Class 72, Metal Deforming, United States Patent Office Classification, Subclass 356 appears to be the applicable general area of art to which the subject matter similar to this invention has been classified in the past.
2. Description of the Prior Art
This invention relates to an improved method of forming a number of sizes of hollow shaft nut drivers from a common tube size. Heretofore, it has been proposed to cold form elongated nut drivers from a tube workpiece by driving the tube workpiece into a die cavity means with a power operated punch for reducing both the inside and outside diameters of one end of the tube workpiece and along a predetermined length of the tube workpiece, so as to form a longitudinally extending shaft of reduced diametrical dimensions relative to the original diametrical dimensions of the tube workpiece. The last described prior art cold forming method is disclosed in U.S. Pat. No. 4,594,874. A disadvantage of said prior art cold forming method is that it requires a tube workpiece having a separate diameter for each nut driver size desired to be produced.